Door hold button circuit



June 12, 1956 J. H. BORDEN ETAL 2,750,005

DOOR HOLD BUTTON CIRCUIT Filed July 20, 1953 L-/ L-Z A3 EMERGENCY 000/? CLOS/NG A? M) STOP AND CA1? GOA/7R0 L5 $7I4R77/V6 CONTROL IN V EN TOR$ JOSEPH H. BURDEN GILES J MUNDY United States Patent 9 DOOR HOLD BUTTON CIRCUIT Joseph H. Borden and Giles J. Mundy, Toledo, Ohio, assignors to Haughton Elevator Company, Toledo, Ohio, a corporation of Ohio Application July 20, 1953, Serial No. 369,153

Claims. (Cl. 187-29) This invention relates to elevators intended to be controlled by push buttons operated by the passengers without the assistance of an attendant and more particularly to an auxiliary door operating control circuit for suspending operation of the door reclosing circuits when additional time is required for loading or unloading the elevator. I

Automatic elevators equipped with door reclosing circuits are ordinarily arranged that the doors remain open long enough for the passengers to leave or enter the car. This time interval is found to be much too short when freight or packages are to be loaded or, in hospitals, when stretchers have to be wheeled into or from the car. In such cases it has been necessary for some person to hold the doors open while loading or unloading the car.

The principal object of this invention is to provide an auxiliary door operating control including a push button in the elevator car which control, when the button is pushed, suspends operation of the door reclosing and car starting circuits and holds such circuits inoperative until the button is either manually released or until a predetermined longer time interval has elapsed.

Another object of the invention is to provide means for suspending operation of the door reclosing circuits during a time interval that is sutficiently long to allow freight to be loaded or unloaded.

Another object of the invention is to provide a timer that cooperates with the door operation suspending circuit to return the door circuits to normal operation should a departing passenger forget to release the door-hold button when he leaves the car.

Another object of the invention is to provide a manually operable control button that may be manually held partially depressed to suspend the door reclosmg operation and that is automatically held depressed once it 1s depressed to its full extent.

Other objects and advantages are apparent from the following description of a preferred embodiment of the invention.

According to the invention a push button is provided in the elevator car which button controls two sets of contacts; a first set that is connected in series with the door reclosing and our starting circuits, and a second set of contacts that is adapted to energize electromagnetic holding means adapted to hold the button in depressed or operated condition once it is pressed and until the button is either manually returned to its original position or its holding circuit is interrupted by a timer or by manually operated means. The button may be arranged so that by partially depressing it only the first set of contacts are closed and the contacts open as soon as the button is released.

A specific circuit embodying the invention is illustrated in the accompanying figure.

The single schematic figure and the accompanying description are intended merely to illustrate the invention but not to limit its scope.

A circuit for suspending operation of the door reclosing and car starting controls is illustrated in the accompanying figure in which power for the control circuits is supplied from lines L1 and L2. From the line L1 current may flow through emergency stop controls; a first set of contacts 10 of a push button control 11; a lead 12; and door reclosing and car starting control circuits illustrated generally by the rectangle 13. From these circuits current returns through a lead 14 to the return line L2. The push button 11 is normally held in its inoperative condition by a spring 15. When it is desired to suspend operation of the door reclosing and car starting controls the push button 11 is manually pressed to its operated position wherein it opens its contacts 10 and closes another or second set of contacts 16. The second set of contacts 16 are included in a circuit from the line L1 through a lead 17, the now closed contacts 16, contacts 18 of a control circuit relay 19, a lead 20, an electromagnetic holding coil 21, a lead 22, a rectifier 23, timer control contacts 24 and a door release push button 25 and then through a lead 26 to the return line L2. The electromagnetic holding coil 21 is bypassed by a condenser 27 so that direct current components flow through the holding coil 21 while the alternating current components pass through the condenser 27. Also connected in parallel with the holding coil 21, rectifier 23, etc. is a timer 28 arranged to open its contacts 24 and release the door hold button 11 after a time interval long enough to allow loading or unloading of the car. Direct current is supplied to the coil 21 to provide quiet operation of the coil.

The control relay circuit 19 has an operating coil 29 that is controlled from the door closing and car starting control circuits and has a second set of contacts 30 that are connected through leads 31 and 32 so as to be effectively in parallel with the first set of contacts 10 of the push button 11.

The control relay 19 is energized so as to open its contacts 18 and close its contacts 30 as the elevator car accelerates when leaving a floor and remains energized as the car approaches the next landing, completes its final slow down period, and until the brake is set as the car stops at the landing. The contacts 30 closed by this relay prevent any interruption of the door closing and car starting control circuits if the push button 11 is operated after the car has started. Furthermore, the contacts 18 which are opened as soon as the car starts and remain open until the brake sets with the car at rest at the next landing prevent the push button 11 being held in its operated position should the button be pushed while the car is in motion.

The door control release push button 25 is optional in this circuit since the push button 11 may be manually withdrawn to its non-operated condition thereby separating the contacts 16 to tie-energize the holding coil 21.

This circuit in addition to the ordinary circuits used with automatic elevators provides for those situations when it is desired to hold the doors open for more than the usual passenger transfer or loading time. This delayed reclosing of the doors is necessary if the elevator is occasionally used for light freight and thus gives time for loading or unloading the freight, it may also be used in hospitals where additional time may be required to wheel a stretcher into or out of a car, or in other similar situations.

The timer 28 is ordinarily adjusted so that it provides ample time for the additional loading or unloading operation and may be set to provide an excess of time to assure that it will never time out before the required loading operation is completed. This timer 28 could be eliminated if one could be sure that the persons using the elevator would always be sure to return the push button 11 to its non-operated condition before they left the ele vator. Otherwise, if the push button 11 is left in its depressed condition the car cannot start to answer calls at other floors and thus, in effect, is taken out of service. The timer 28 guards against this inadvertent suspension of elevator service by providing that, at the expiration of the time interval, the push button holding coil 21 will be de-energized to allow the button 11 to return to its unoperated position.

The contacts 18 of the control relay 19 serve two purposes. First they prevent operation of the push button holding coil until the car stops at a floor and, second, they prevent premature operation of the timer 25 and thus ensure that a full interval of time will always be allotted to the loading and unloading time.

This arrangement prevents unnecessary operation of the door-hold circuits since uninformed passengers may press the button, thinking that necessary to open the doors. However, the button will not be held down unless pushed after the doors have started to open, thus the probability of false operation is materially lessened.

The push button 11 may be arranged to open the contacts without closing the contacts 16 when it is partially depressed. As long as the button 11 is thus manually held partially depressed the doors will not reclose but since the holding coil 21 is not energized the button is not automatically held. In order that the passenger know when he has pushed the button far enough to open the contacts 10 a collar 33 on the push button rod is arranged to engage a spring 34, which may be preloaded, after the contacts 10 separate and before the contacts 16 engage. This provides an easily felt change in resistance, as the button is being pushed, marking the intermediate or partially depressed position.

This optional feature allows a passenger to hold the doors open by continued pressure on the button 11 and closing them by merely releasing the button.

Various modifications in the structure of the push button or in its operation may be made without departing from the scope of the invention.

Having described the invention, we claim:

1. In an automatic elevator control system in combination, a push button in the elevator car adapted to be operated by an occupant of the car, a contact that is opened by operation of the button and that is connected in series with the car operating controls to prevent when opened the closing of the elevator car doors and movement of the car, a second contact operated by the push button, an electromagnetic holding coil and armature for holding the push button in operated position, said holding coil being energized through the second contact, a relay operated by closing of the doors and starting of the car, contacts on the relay for shunting the first contact, other contacts on the relay in series with the second contact, an electrically operated timer that is energized through said second contact, and timer contacts that are opened by said timer after a time interval, said timer contacts being connected in series with said holding coil whereby said push button is released at the expiration of the time interval.

2. In an automatic elevator control system, in combination, a push button in the elevator car adapted to be operated by an occupant of the car, a first contact that is opened by operation of the button and that is arranged to prevent closure of the car doors and operation of the car, a second contact that is closed by operation of the push button, means for preventing response to said push button when the doors are closed and the car is in motion, electromagnetic means energized through the second contact operatively connected to hold the push button in operated position, said button having an operable portion protruding by which it may be withdrawn to its nonoperated position, an electrically operated timer that is energized through the second contact, and timer operated contacts connected to de-energize said electromagnetic means at the expiration of the timer interval.

3. In an automatic elevator control system, an auxiliary control for lengthening the loading interval during which the elevator car doors are held open, said control comprising a manual push-to-operate pull-to-release button, a first contact that is opened by operation of the button connected in series with door operating and car starting controls of the elevator, a second contact that is closed by operation of the button, means preventing response to the push button when the doors are closed and the car is in operation, electromagnetic holding means operatively connected to the button for holding the button in operated position, said holding means being energized through said second contacts, a timer that is energized through said second contacts, and contacts opened by the timer and connected in series with the holding means for releasing the button after a predetermined time interval.

4. In an automatic elevator control system, an auxiliary control for lengthening the loading time interval, said auxiliary control comprising a manually operable push button, a first contact opened by operation of the push button and arranged to suspend operation of the door closing and car starting controls, a second contact closed by operation of the push button, means preventing response to said push button when the doors are closed and the car is in motion, electromagnetic holding means energized through said second contact for holding the button in operated condition, manually operable means for de-energizing said holding means, a timer that is energized through the second contact and contacts opened by the timer arranged to de-energize the holding means.

5. In an automatic elevator control system, an auxiliary control for lengthening the loading time interval, said auxiliary control comprising a manually operable push button, a first set of contacts that are opened by initial movement of the push button and arranged to suspend operation of the door closing and car starting controls, resilient means adapted to increase the resistance of the push button to pushing after said first contacts are opened, a second set of contacts that are closed by further movement of the push button, means for preventing response to the push button when the doors are closed and the car is in motion, electromagnetic holding means energized through the second contact for holding the button in operated condition, and a timer that is energized through said second set of contacts and that has contacts adapted to break the circuit to said holding means.

References Cited in the file of this patent UNITED STATES PATENTS 2,539,206 Robinson Jan. 23, 1951 

